1. Field of the Invention
The present invention relates to an air cleaner for a portable engine and, more particularly, to an air cleaner suitable for a portable engine for driving a backpack blower, a backpack power applicator or a hand held bush cutter.
2. Description of the Related Art
FIG. 10 shows a known portable engine E disclosed in JP-A No. 2002-303148 by way of example. This engine is used for driving a backpack blower A as shown in FIG. 9. The backpack blower A includes an engine E, a blower 1, a back frame 15 holding the engine E and the blower 1, a flexible pipe 16 connected to the discharge pipe of the blower 1, a duct 17, and a nozzle 18. An operator supports the back frame 15 holding the engine E and the blower 1 on the operator's shoulders by straps 19 connected to the back frame 15. Air is blown through the nozzle 18 to blow and collect dead leaves M and trash.
Referring to FIG. 10, an exhaust muffler 11 is joined to one of the opposite sides of a cylinder 8, and an intake pipe (insulator) 7, a carburetor 12 and an air cleaner 13 are connected in that order to the other side of the cylinder 8. The cylinder 8 and the exhaust muffler 11 are covered with a shroud 21. The air cleaner 13 has an intake duct 100 opening downward.
In the prior constitution shown in FIG. 10, since the air cleaner 13 is arranged in the lateral of the carburetor 12 and is joined to the carburetor 12 connected to the intake pipe 7, the air cleaner 13 juts out greatly laterally and increases the width of the engine E. When the engine E is used for driving the backpack blower 1 as shown in FIG. 9, the greatly laterally jutting air cleaner 13 obstructs the cleaning work.
When the volume of the air cleaner 13 is increased to enhance the output of the engine, to reduce the noise of the intake air of the engine, or to extend the useful life of the air cleaner element, the air cleaner 13 needs to be formed of a high-strength material or to be provided with reinforcing members to make the air cleaner 13 sufficiently durable, because the air cleaner 13 juts out laterally from the carburetor 12 connected to the intake pipe 7 as shown in FIG. 10. As a result, the cost and the weight of the air cleaner 13 increase.
Since the intake duct 100 of the air cleaner 13 opens simply downward, it is possible that blown dead leaves and trash stick to the open lower end of the intake duct 100 to reduce the flow of intake air suddenly.